Transcript PRESENTATION NAME

Tweaks and Fixes: New Developments in
Improving Quality and Managing
Problems
Alan Marks
Scott Laboratories Ltd.
Acknowledgements
• Lallemand www.lallemand.com
• Dominique Delteil, Lallemand Consultant &
former director of the ICV (Institut Cooperératif
du Vin) www.icv.fr
Defining Grape Quality
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Varietal aroma/flavour
◦ herbal, green >>>> jammy
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Skin tannin quality
◦ harsh, astringent >>>>>soft, supple
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Seed tannin development
Brix, total acidity, pH
Fruit condition and berry size
Defining Wine Quality
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Clean, complex aromas & flavours
Fullness & concentrated flavours
Balance of acid/alcohol/residual
sweetness
Refinement, lack of harshness,
astringency or bitterness
Colour quality (intensity & hue) in reds
Long finish
Ten Winemaking Commandments
1. Thou shalt not use DAP
2. Thou shalt press thy whites gently
3. Thou shall use fermentation tannins for reds
4. Thou shall use rehydration nutrients
5. Thou shall use only organic yeast nutrients
6. Thou shall not add SO2 to an active ferment
7. Thou shalt not ferment reds above 25 C
8. Thou shall use co-inoculation for MLF
9. Thou shall rack thy reds and whites quickly
10. Thou shalt not use cheap or synthetic corks
Coinoculation, Yeast & MLB
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Prior History, mainly with red wines
Bacteria grow slowly until yeast death
phase
Yeast growth not affected by bacteria
Yeast autolysis gives bacteria nutrients
Bacteria consume malic first, then citric,
fumaric, then sugars if pH > 3.5
Coinoculation (cont.)
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German research with Riesling
◦ Diacetyl degraded by active yeast
◦ Final coinculated wines, fruitiness
preserved
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For high pH reds
◦ Primary fermentation must complete
Practical Considerations
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Don’t use high SO2 producing yeast
Bacteria added 1-2 days after yeast, when
things start warming up
MLB added at half normal rate
Careful monitoring of fermentation, malic by
chromatography and VA
Sulfite added quickly after MLF completes
Tannin Benefits
Help stabilize colour
Enhance structure (mouthfeel)
Inhibit laccase activity (grapes
with botrytis)
Enhance aging potential
Key Concepts on Sulfury Odours
• Sulfur Odours (S.O.) can be hard to identify, they
saturate the senses quickly
• Every practice in the winery and the vineyard
may influence sulfury odours
• S.O.’s have other side effects mainly masking
other aromas and changing mouthfeel
How can S.O.’s affect mouthfeel?
• Sulfur compounds not 100% volatile at room
temperature, the part in solution is aggressive to
the mouth mucous membrane
Main Compounds Involved in S.O.’s
• Sulfur compounds produced by yeast
▫ Saccharomyces
▫ Brettanomyces et. al. Brett’s first impact is
producing s.o.’s, long before E4P is smelled
--Compounds produced during fermentation
will form stable derivatives with S.O.’s
--Macromolecules can enhance or diminish S.O.
intensity
Challenges with High Brix Grapes
• High risk of s.o.’s produced by the yeast due to
low nutrients and high osmotic shock
• Final high alcohol enhances volatile aromas and
enhances astringency and bitterness
• Need to develop and stabilize polysaccharides
• Practices to limit astringency and bitterness
Key Tools to Consider
• Maceration Enzymes
▫ earlier yeast access to nutrients?
▫ earlier polysaccharide/sulfur cmpd interactions?
▫ better and earlier racking, less lees contribution
to S.O.’s
• Selected Yeast Strain
• Yeast Nutrients
Key Practice to Consider (reds)
• Délestage (rack and return)
▫ extracts more macromolecules
▫ helps tannin stabilisation
▫ limits s.o. production
 making oxygen available for all yeast
 complete yeast stirring (mix up lees)
 physical stripping of H2S by aeration
Main Factors for S.O. Production
(whites and roses)
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Sulfur from vineyard sprays and some pesticides
Turbidity greater than 150 NTU
Yeast Stress
For Reds, include:
▫ Lees at the end of fermentation left too long
▫ Unsuitable strain of ML bacteria
▫ Presence of Brett, Pediococcus or Lactobacillus
Twelve Steps for Preventing Sulfur OffAromas in Whites and Rosés
• Critical period for S.O. precursor production is
from 22+brix to ~5 brix. Around day 1 to 10
• Critical to perceive any developing S.O.’ from
~10 brix to dryness in order to take early
corrective actions. Around day 7 to 21.
Twelve Steps for Preventing Sulfur OffAromas in Whites and Rosés
1. Have turbidity levels less than 150 NTU
2. Add ascorbic acid to grapes or 50 mg/l to juice
after settling and racking
3. Choose low sulfur odour producing yeast strain
4. Rehydrate yeast with sterols (GoFerm)
5. Add nutrient (Fermaid O) to juice at inoculation,
rate of 20 g/hl
6. Add inactive yeast product (OptiWhite,
BoosterBlanc) to juice at time of inoculation
Twelve Steps for Preventing Sulfur OffAromas in Whites and Rosés
7. Add 6 mg/l oxygen (macro) at ~2 brix depletion
from the starting brix
8. Add nutrient, 20 g/hl, at ~7 brix depletion
9. Add 8 mg/l oxygen (macro) at same time at in step
7 and again the next day
10. Keep temp. at 16-18 C from 17 brix to 0 brix
11. Regular mixing (Guth or pumpover, no O2)
12. Add SO2, 20 mg/L and ascorbic acid, 30 mg/L
right after dryness and rack 24 hrs after (unless ML
desired)
Yeast Inoculation Modification
• Rehydration as usual, added sterols optional
• Transfer first rehydration mixture to 2% of total
juice volume to be inoculated, equalizing
temperature gradually
• Aeration of this starter for 6-8 hours before
pitching into main tank
Main Curative Actions,
whites & rosés
• If still S.O.’s after first racking (SO2 and ascorbic
added) and if followed the 12 steps
• Add 30 g/hL inactive yeast (OptiRed, BoosterRouge
or BoosterBlanc) with mixing once/day for a week
with no O2.
• Do bench trials with copper sulfate
Modified Copper Procedure
• Treat wine with 50% of amount needed as
determined in the bench trial
• Mix daily (no O2) for a week
• Keep molecular SO2 at 0.8 to 1.0 mg/l
• Add 1 g/hl ascorbic acid on day 8 and rack
avoiding O2
• mix twice/week for a month keeping molecular
SO2 at above level
What to do if didn’t follow 12 steps?
Depends on what stage S.O.’s perceived
▫ 22+ brix to ~12 brix
▫ 12 brix to ~5 brix
▫ 5 brix to dryness
More involved procedures, call or email
Twelve Steps for Preventing Sulfur OffAromas in Reds
1. Use selected yeast strain, esp. “D” types
2. Rehydrate yeast with sterols (GoFerm)
3. Add nutrient to must at yeast inoculation, 2030 g/hl
4. Add inactive yeast at inoculation (OptiRed,
BoosterRouge)
5. Limit temperature during yeast growth to 25 C
or below
6. Add 10 mg/l O2 at 2 brix depletion from start
Twelve Steps for Preventing Sulfur OffAromas in Reds
7. Add nutrient, 10-20 g/hl at ~7 brix depletion
8. Add 10 mg/l O2 at same time as step 7 and
repeat the next day
9. Keep temperature during this yeast stationary
phase to 25 C or less
10. Regular mixing of juice/cap
11. After pressing, rack off lees around 24 hrs later
12. Inoculate with selected ML strain (VP41, Elios)
Extra consideration would be micro-oxygenation
Main Curative Actions, Reds, if
followed the twelve steps
• Same as for whites/roses using inactive yeast
with mixing
• Copper procedure same except keeping SO2 to
around 0.5 mg/l to facilitate MLF.
What to do if didn’t follow 12 steps?
• Same as whites, depends on stage noticed
Thanks for your attention and good
luck with your winemaking!
Alan Marks
Scott Laboratories
Technical Sales Representative
phone: 250-769-9463
fax: 250-769-9477
cell: 250-859-6466
[email protected]